Advisory committee on immunization practices




Скачать 435.53 Kb.
НазваниеAdvisory committee on immunization practices
страница3/10
Дата24.09.2012
Размер435.53 Kb.
ТипДокументы
1   2   3   4   5   6   7   8   9   10

Vote

In favor: Allos, Beck, Campbell, Finger, Gilsdorf, Hull, Lieu, Marcuse, Morita, Treanor, Womeodu, Abramson

Opposed: None

Abstained: None


The vote passed.


HEPATITIS A


Recommendations for Hepatitis A Vaccination of Children

Presenter: Dr. Beth Bell, N.C.I.D.


Overview: Review of hepatitis A epidemiology; progress of past and current recommendations’ implementation; proposed language on: 1) routine vaccination of 1 year old children nationwide; 2) maintaining vaccination of 2 to 18 year old children in areas with existing programs; and 3) consideration of vaccination of 2 to 18 year old children in areas without existing programs.


A.C.I.P. recommendations for hepatitis A vaccination of children have been implemented incrementally, beginning in 1996 with vaccination of children living in so-called “high rate” communities. In 1999, the A.C.I.P. took another incremental step by recommending routine vaccination of children living in states and communities with hepatitis A incidence rates that were consistently higher than the national average during a defined baseline period in the pre-vaccine era. The A.C.I.P. indicated that the final step in the incremental strategy was routine vaccination of all children nationwide, and that implementation of this policy would be facilitated by the availability of hepatitis A vaccines for use in children aged less than 2 years. Routine vaccination of children nationwide would allow consideration of elimination of indigenous hepatitis A virus (H.A.V.) transmission.


The 17 states in which, according to the 1999 A.C.I.P. recommendations, routine hepatitis A vaccination of children was recommended or should be considered include approximately 33 percent of the U.S. population, but approximately 66 percent of the reported hepatitis A cases during the pre-vaccine era baseline period.


The 1999 recommendations included permissive language with respect to implementation strategies. They suggested determining the age groups to be vaccinated based on community disease patterns and proposed a number of possible vaccination strategies (for example, one or more single-age cohorts, in selected settings such as day care, or children in a wide age range when they presented for medical care). As a result, approaches and implementation have varied considerably among the states in the five years since the recommendations were made.


Current vaccination coverage.

  • National Immunization Survey, 2003 and 2004: One-dose coverage among children aged 24 to 35 months averaged 51 percent to 54 percent in the 11 states where vaccination was recommended (range 6 percent to 74 percent), 25 percent to 27 percent in the 6 states where it was to be considered (range 1 percent to 35 percent), and 1 percent to 2 percent in the other states.

  • Preliminary results of a C.D.C.-R.T.I. telephone survey (with provider verification of immunization record) in Arizona and Oregon indicate approximately 70 percent coverage among 2½ to 5 year-old children in those states, declining to approximately 25 to 30 percent among older children.

  • Although information on trends in vaccination coverage is limited, available data suggest that coverage appears to be rising slowly, if at all, in recent years. Implementation has been accomplished primarily using voluntary strategies, and few states have mandates. There has been little change in states’ vaccination policies in recent years.


Remarkable changes in hepatitis A epidemiology have been observed since implementation of the 1999 recommendations. Overall incidence has declined, with sharper declines in the areas in which vaccination was recommended. In 2004, the incidence rate was 1.9 per 100,000 ─ the lowest rate in the approximately 40 years that these data have been collected. Declines occurred in all age groups, but were greater among children. In the pre-vaccine era, rates among children were consistently higher than those of adults, but since 2001, rates among children have been lower than among adults. Differences in hepatitis A incidence among racial/ethnic groups also have narrowed or been eliminated. In the pre-vaccine era, hepatitis A incidence among American Indians and Alaska Natives was approximately10 times higher than among whites, but currently is among the lowest of any racial/ethnic group. Rate differences between Hispanics and non-Hispanics have also narrowed, although rates remain higher among Hispanics.


In examining recent trends in hepatitis A incidence by age group, it can be seen that the rates among children aged 2 to 9 years living in areas where vaccination is recommended steadily declined to 2003 and then plateaued in 2004. Among children living in areas where vaccination is not recommended, there was a slight increase in incidence in 2004 compared to 2003, and this group had the highest age- and region-specific rate in 2004. A similar pattern was observed for those aged 10 to 18 years, with plateauing of rates in both vaccinating and non-vaccinating regions. Incidence rates among adults continued to decline in both regions and most of the overall decline in incidence between 2003 and 2004 was attributable to declines among adults.


The distribution of cases by age group and region during the pre-vaccine era and in 2004 was compared. The overall proportion of cases among children fell from approximately 36 percent to 27 percent. Whereas in the pre-vaccine era approximately two thirds of all cases were reported from states in which vaccination was then recommended, in 2004 cases from these vaccinating states accounted for about one third of cases and approximately 66 percent of cases in 2004 occurred in areas not using vaccine.


In vaccinating states, the incidence among Hispanic children has dramatically declined, to 2.9 per 100,000, but this rate remains somewhat higher than among non-Hispanic (0.5 per 100,000) children. In the non-vaccinating states, the difference in the incidence rate between Hispanic (7.1 per 100,000) and non-Hispanic (1.0 per 100,000) children remains large. The 2004 rate among Hispanic children in non-vaccinating states was the highest age-specific rate in either vaccinating or non-vaccinating states.


In summary, the overall hepatitis A incidence rate has continued to fall in recent years, primarily because of continuing declines among adults; rates among children appear to have plateaued. Despite this progress, about 5,000 to 7,000 cases are reported each year, and an estimated 20,000 to 30,000 symptomatic cases occur. Rates are similar across regions, and are highest among Hispanic children in non-vaccinating states. Most cases are reported from states without routine vaccination recommendations.


Although difficult to predict with any certainty, if the current A.C.I.P. recommendations were to be maintained unchanged, theoretical models of incidence dynamics when a new vaccine is introduced predict an initial nadir followed by a rebound to a new steady state, which will be lower than before vaccine introduction but higher than the nadir. A model of expected incidence predicts 5000 to 11,000 cases per year over the next ten years without immunization in the non-vaccinating states.


Nationwide vaccination of children with hepatitis A vaccine will move this childhood vaccination into the mainstream, improving its sustainability and increasing the probability of achieving high coverage. It is consistent with the incremental strategy. The availability of two vaccines for use from 12 months of age will allow the incorporation of hepatitis A vaccine into the routine childhood vaccination schedule. Nationwide routine vaccination of children is likely to result in lower rates over time, to further narrow demographic disparities, and allow eventual consideration of elimination of indigenous transmission. The economic analyses of this strategy are favorable.


Working Group Discussions/Economic Analyses

Presenter: Dr. Tracy Lieu, Working Group Chair


In early September, a poll of A.C.I.P. members revealed general support for universal hepatitis A vaccination, although a few members were undecided. The A.C.I.P. hepatitis vaccines Working Group also supported universal vaccination. Several key questions arose from the working group deliberations as well in discussions with other A.C.I.P. members:


Why is universal vaccination needed now? The 1999 A.C.I.P. recommendations for “high-incidence” states were an interim step; A.C.I.P.’s intent has always been to eventually implement nationwide hepatitis A vaccination. Hepatitis A vaccines are now available for use in one-year-olds, improving the feasibility of this strategy, as initially envisaged by the A.C.I.P. Finally, the current policy of vaccination in “high-incidence” states is not sustainable.


Why is the status quo not sustainable? The policy of selective vaccination is not sustainable because states that used to be “high-incidence” now have lower incidence than the “low-incidence” states where vaccination is not recommended. Hence the rationale for continued vaccination in these areas doesn’t make sense to people, and anecdotal evidence suggests that states may lose support for continued vaccination. Even if selective vaccination were sustainable, its impact probably would not be sustained, as shown by plateaued disease rates among children and the persistence of disparities. Without universal vaccination, models predict that hepatitis A incidence probably would rise again.


Cost-benefit of universal vaccination. Predictions of the C.D.C.-R.T.I. economic model were summarized.

Health Benefit (annual, with vaccination at age 1 year):

  • Retaining the status quo is predicted to prevent 81,000 cases, or 41 percent of potential cases, versus the 199,000 cases with no vaccination. Eleven lives and 1,100 quality-adjusted life-years (Q.A.L.Y.s) would be saved. Expanding the policy to nationwide vaccination would prevent 180,000 (or 90 percent) hepatitis A cases, saving 32 lives and 2,300 Q.A.L.Y.s.

  • The incremental difference in health benefits is 99,000 (49 percent) hepatitis A cases prevented, 21 lives saved, and 1,200 Q.A.L.Y.s saved.


Costs (annual, with vaccination at age 1 year):

  • Vaccine doses and administration would be 48 dollars per child in either the status quo or nationwide strategy. The 22 million dollars direct vaccination costs for the status quo would rise to 134 million dollars with nationwide vaccination, an incremental cost of 112 million dollars. Vaccination in the status quo scenario saves 18 million dollars. The net societal cost of vaccination nationwide is 45 million dollars.


Cost-effectiveness

  • The status quo is cost saving with respect to Q.A.L.Y.s and dollars-per-life-year saved. With nationwide vaccination, the cost per Q.A.L.Y. would be 25,000 dollars and per life year saved, 180,000 dollars. The “incremental” benefit, the difference between the status quo and nationwide vaccination, was estimated to be 60,000 dollars per Q.A.L.Y. and 430,000 dollars per life year saved.

  • A comparison was made of the economics of nationwide hepatitis A vaccination compared to other recently-recommended vaccination policies -- adolescent pertussis vaccination and meningococcal vaccination. Implementation of the respective vaccination policies would prevent an estimated 180,000 hepatitis A disease cases, 31,000 pertussis disease cases and 270 cases of meningococcal disease, respectively. The hepatitis A program saved slightly more Q.A.L.Y.s than the other two vaccination policies. Its direct vaccination cost (134 million dollars) rested between pertussis and meningococcal vaccination, and its net societal cost of 45 million dollars was closer to that of pertussis (33 million dollars) than to meningococcus (159 million dollars). The cost per Q.A.L.Y. saved of universal hepatitis A vaccination of one year olds of 25,000 dollars was similar to the estimate for pertussis vaccination of adolescents (20,000 dollars) and less than that for meningococcal vaccination (138,000 dollars).

  • In summary, universal hepatitis A vaccination of one year old children would more than double the benefit compared with the status quo. And, while it would increase the direct cost of vaccination (six fold), the CE is very reasonable compared to other vaccines.


For these reasons, the Working Group reached consensus to support this recommendation. However, they also agreed that the added vaccine financing of this and other new vaccine recommendations needs to be addressed in the larger context of A.C.I.P.


Proposed Recommendation Wording

  • Routine vaccination of young children: All children should receive hepatitis A vaccine at 1 year of age (that is, 12 to 23 months). Vaccination should be completed according to the licensed schedules and integrated into the routine childhood vaccination schedule. Children who are not vaccinated by 2 years of age can be vaccinated at subsequent visits.

  • Older children and adolescents in areas with existing programs (catch-up vaccination): States, counties, and communities with existing hepatitis A vaccination programs for children aged 2 to 18 years are encouraged to maintain these programs. In these areas, new efforts focused on routine vaccination of 1 year old children should enhance, not replace, ongoing programs directed at a broader population of children.

  • Older children and adolescents in areas without existing programs: In areas without existing hepatitis A vaccination programs, catch-up vaccination of unvaccinated children aged 2 to 18 years can be considered. Such programs might especially be warranted in the context of rising incidence or ongoing outbreaks among children or adolescents.


Discussion:

  • Preschool children were not included in this recommendation to avoid having to vaccinate all four cohorts to preschool age, particularly since not all the vaccines were licensed for one year of age. The adult disease rates might invite an adult vaccination platform; the Working Group did not wish to address the existing adult recommendations at this time.

  • Despite better hygiene, etc., C.D.C. does not expect the hepatitis A disease cycles to change. They are currently in a downward cycle that will not continue, but when they rise again, they are unlikely to go to pre-vaccine levels.

  • There is indirect evidence that many adult cases stem from children. There were “huge” rate declines among adults in the states that vaccinated children. A published C.D.C. model of vaccination impact through 2001 estimated that about a third of the program’s impact might be attributable to herd immunity.

  • The disease analysis did not assume lifelong immunity to hepatitis A. Dr. Armstrong explained that the economic analysis assumed a 93 percent one-dose immunization coverage at age one year, and approximately 85 percent for two doses. Belgian data on declining antibody levels among vaccinated individuals were incorporated in a model to estimate the duration of immunity. The current data support immunity to 12 years post-vaccination, and long term protection of at least 20 years is expected based on modeling studies.

  • Dr. Diane Peterson, of the Immunization Action Coalition, suggested that the recommendation advise vaccination for “all children aged 12 to 35 months with catch-up vaccination all throughout the pre-school years.” She also advised adding children aged ≥5 years with risk factors for vaccination to the routine schedule. Dr. Baker expressed A.A.P.’s strong support for clarification that primary immunization occurs from 12 to 25 months and all else is catch-up.

  • With the impending release of M.M.R.V., zoster, rotavirus, and H.P.V. vaccines, Dr. Katz urged prioritization that is related to the overall costs, to avoid disruption of the V.F.C. entitlement program. Dr. Abramson reported very different feelings about prioritization among A.C.I.P. members, but all agree that if the financial problems are not solved, nothing will come of the recommendations.

  • Dr. Cochi stated that it is not the A.C.I.P.’s primary responsibility to solve the financing problem, but only to examine the cost benefit and other considerations. However, an A.C.I.P. recommendation is an important stimulus to attention to this crisis. Dr. Plotkin firmly stated that A.C.I.P.’s role is to recommend on public health, and its recommendations should be based only on that. Dr. Orenstein added that Congress’ intent, in establishing the V.F.C. program in 1993, was to keep other groups from recommending on these issues because the cost issues might bias them. Dr. Hull agreed, noting that congressional seats change and congress’ attention is only caught for short periods of time. Recommendations to Congress should be based only on what is necessary for public health.

  • Dr. Tim Townsend, of Johns Hopkins, had examined this question from different aspects: stopping vaccination, which endangers the public health, or continuing the status quo, in which states with rising rates will have to be funded. Since funds from other states cannot be diverted for that, the only obvious answer is universal recommendation.


Dr. Lieu moved to support the hepatitis A recommendation with the friendly amendments to clarify it. Dr. Campbell seconded the motion.

Vote

In favor: Allos, Beck, Campbell, Finger, Gilsdorf, Hull, Lieu, Marcuse, Morita, Womeodu, Abramson
1   2   3   4   5   6   7   8   9   10

Похожие:

Advisory committee on immunization practices iconJane D. Siegel, md; Emily Rhinehart, rn mph cic; Marguerite Jackson, PhD; Linda Chiarello, rn ms; the Healthcare Infection Control Practices Advisory Committee

Advisory committee on immunization practices iconRanch hand advisory committee

Advisory committee on immunization practices iconVeterinary medicine advisory committee

Advisory committee on immunization practices iconMedical Devices Advisory Committee

Advisory committee on immunization practices iconExternal Advisory Committee on Cities and Communities

Advisory committee on immunization practices iconWildlife Diversity Policy Advisory Committee

Advisory committee on immunization practices iconNational Vaccine Advisory Committee (nvac)

Advisory committee on immunization practices iconPeer reviewed by the Arizona Department of Commerce Economic Research Advisory Committee

Advisory committee on immunization practices iconFood and drug administration national institutes of health advisory Committee on: transmissible spongiform

Advisory committee on immunization practices iconAdvisory Committee, Cuyahoga Valley School-to-Career Consortium, Broadview Heights, Ohio 1996-2002

Разместите кнопку на своём сайте:
Библиотека


База данных защищена авторским правом ©lib.znate.ru 2014
обратиться к администрации
Библиотека
Главная страница